Though Cubs starter threw 89 pitches in 52/3 innings, he retired side on 3 pitches in 3rd even with leadoff bunt single

Edwin Jackson threw 89 pitches in just 52/3 innings Saturday. But in the third, the Cubs right-hander finished off Reds hitters Billy Hamilton, Joey Votto and Brandon Phillips with just three pitches.

Hamilton started the inning with a bunt single, but Votto bounced into a double play on his first pitch and Brandon Phillips went down pitcher to first.

The last Cubs pitcher to record three outs on three pitches in an inning was Randy Wells on Sept. 25, 2011 against the Cardinals, according to STATS.

Precautionary measure: First baseman Anthony Rizzo left Saturday's game in the eighth inning with back spasms.

"It just started barking on me in about the fifth or sixth (inning)," Rizzo said. "Once we took the four-run lead, I kind of played it with more caution."

Rizzo said he initially felt a little discomfort Friday but expects to be available for Sunday's series finale.

"It's weird," he said. "It was just a play on a pickoff (attempt) that was kind of high and I jumped up. That's when it started barking the most."

Almost ready: Right-hander Jake Arrieta, on the disabled list with right shoulder tightness, is scheduled for another minor league rehab start Monday at Daytona.

"I'm just one step away from being really locked in," Arrieta said. "It feels good. I don't think I will be 100 percent until I get (to Wrigley), get in a game and kind of pitch at that intensity for the first time. But I am right where I need to be right now."

Loyalty: The Cubs drew 32,966 fans Saturday and are averaging 29,655 through eight home games.

"That's awesome. I love it," manager Rick Renteria said of the fans support. "We're hoping to move the process forward. Guys are going to get better, hopefully. And we will try to play some good baseball and make the corrections we need to."

Extra innings:Hector Rondon's scoreless streak of 162/3 innings came to an end in the Reds' two-run seventh. … Junior Lake has hit safely in eight of his 10 starts, though he's hitting only .239 overall. … The Reds activated left-handed reliever and former Cub Sean Marshall from the disabled list.